HDMI recognized as "unplugged", after installing drivers

Thank you! Running this command mostly solves the problem:

pacmd set-card-profile 0 output:hdmi-stereo

If not, pressing Ctrl+Alt+F1 and then Ctrl+Alt+F7 solves it.

I have the same issue. Each time I suspend the system and wake it up, pulseaduio says HDMI is unplugged. I do the following:

1. Press Ctrl+Alt+F1 to go to a terminal log in.

2. Then press Ctrl+Alt+F7 to go back to the GUI.

After that, pulseaudio says HDMI is plugged in (under Output Device).

I had the exact same thing with an old Radeon 6900 Series.

To see info on pulseaudio devices:

pacmd list-cards

Look for the card's index and, under that, profiles. For instance, I had:

2 card(s) available.
   ****index: 0****
    name: <alsa_card.pci-0000_01_00.1>
    driver: <module-alsa-card.c>
    owner module: 6
    properties:
        alsa.card = "1"
        alsa.card_name = "HDA ATI HDMI"
...
    profiles:
        ****output:hdmi-stereo****: Digital Stereo (HDMI) Output (priority 5400, available: unknown)

Those bits of info are then used to set the output profile:

pacmd set-card-profile 0 output:hdmi-stereo

Note that the set-card-profile parameters are the card index (0) and the output (hdmi-stereo).

After that, things just worked.

Queues came from here mostly: PulseAudio reports HDMI Audio is unplugged from the Nvidia MCP79 device

You cant do this on the default sound properties you need pauvcontrol

sudo apt-get install pavucontrol
pavucontrol

go to the configuration Tab

find your device

choose a profile that is plugged.

updated: fixed typo in pavucontrol